Always a problem to cancell

I am utterly disappointed in the poor service I have received from Telkom. I received a notification from telkom telling me that all DSL lines will need to be migrated to Fibre in my area. Sales department contacted me several times to upgrade (they were quick to respond to the sale). Once my Fibre line was installed I contacted the telkom line to cancell my previous DSL line, I contacted telkom twice to make sure my line was cancelled and on both occasions both consultants confirmed my previous line was cancelled. Only once I received my bill I saw they still billed me for my previous and current line. I contacted the telkom line again to confirm if cancelled and the consultant confirmed once again it was cancelled. I told her it can't be because they billed me for the previous line, she checked again on the systems and this is when she realised it was the first contract I had with telkom that showed cancelled and not the previous line I migrated from. She apologized and told me to logg the cancellation request online and dispute this matter on the telkom website as she couldn't not assist. I have received the notification it was cancelled. (just hope it is canceled) I have also logged the dispute regarding a refund twice, on both occasions the consultant only tried to phone once (both times I missed the call) when I tried to phone the number back it does not ring. All I want is a refund on the previous line I have cancelled.